Retrievable well tool hanger



April 18, 1961 D. E. DAFFIN RETRIEVABLE WELL TOOL HANGER 2 Sheets-Sheet2 Filed July 11, 1958 INVENTOR.

ATTORNEY United States Patent RETRIEVABLE WELL TOOL HANGER Douglas E.Datfin, Pasadena, Tex., assignor to Cameo Incorporated, Houston, Tex., acorporation of Texas Filed July 11, 1958, Ser. No. 747,980

8 Claims. (Cl. 166-211) This invention relates to an improved well toolhanger which can be easily lowered in the well string on a wire line andsecurely latched at a given location for supporting a subsurface controldevice, an extension tube or the like, and which hanger can be readilyremoved at any later time. Tool hangers as heretofore constructed haveoften been somewhat complex and costly to manufacture and have beendifiicult to handle from the surface through a flexible line without theexercise of considerable skill in effecting a proper landing at apresumed location and thereafter in careful manipulation to drive aprojecting wedge force behind initially retracted latch do s.

in object of the present invention is to provide in a simplified form aretrievable tool hanger having normally projected dogging or lockingmechanism which responds by its fit to and relative travel in a landingsection for conditioning itself to an automatic latching operationcoincidental to a landing, whereby the need, after a landing has beeneffected, for additionally manually effect-' ing a driving wedge forcebehind normally retracted latching dogs is avoided and difficulties inobtaining secure attachment against accidental displacement areeliminated. A further object of the invention is to provide a selflocking hanger structure which will remain in place against dislodgmentexcept upon the use of a pulling tool for the application of liftingforces, first to break a releasable connection by which a dog projectingabutment theretofore has been held in dog retraction blocking relation,and then to raise the abutment to dog clearing relation for freeing thepreviously anchored hanger.

Other objects will become apparent from the accompanying drawingillustrating a preferred embodiment of the invention and wherein Fig. 1is a view partly in elevation and partly in vertical section showing theimproved hanger construction with its parts as positioned prior to beinglowered into the well; Figs. 2, 3 and4 are fragmentary views partly inelevation and partly in vertical section and respectively illustratingthe latching mechanism with the dogs retracted for downward passage in alanding nipple; with the dogs projected in nipple latching positionandwith the dogs retracted for re moval from the nipple; and Fig. 5 is atransverse section on line 5-5 of Fig. l.

In the drawings a' standard nipple 1 for coupling insertion within atubing string consists of a tubular wall enclosing an inner tubular coreSand mounting one or lmore latch dogs 9 for relative movement bothaxially and laterally of the housing for outward projection andinward'retraction relative to the housing outside. For convenience ofmanufacture and assembly, the outer housing 7 is made up of separateparts 10, 11 and 12 screw threaded together in end to end succession.

The lowermost housing part 12 terminates in a reduced diameter tip 13which is externally screw threaded for mounting thereon an extensiontube or a well tool, as, for example, a conventional choke to controlfluid flow through the tubing string. Packing rings 14 surround areduced diameter neck portion of the housing element 11 and are held inplace by the co-operating lower housing element 12. They are to makesealing contact with the internal surface of a nipple for insuringagainst fluid leakage about an installed hanger.

Near its upper end the housing part 10 has an annular enlargement 15 ofa diameter to fit within the counterbore 2 of the nipple. The bottomshoulder 16 of the enlargement affords a stop seat for abutment with thenipple landing seat 3 at the. downward limit of hanger travel. Spacedslightly below the stop seat 16, the housing part 10 is of reducedoutside diameter to form an annular peripheral groove ,or reduceddiameter portion 17 whose opposite ends are defined by an upper shoulder18 and a lower shoulder 19 conveniently constituted by the upper edge ofthe housing element 11. Slidably sleeved on the reduced portion 17 is acollar or annular band 20 and a helical coil spring 21. One end of thecoil spring bears on the upper shoulder 18 and the other end bears onthe uppermargin of the collar 20 and 7 acts to bias the collardownwardly into abutment at its lowermargin with the shoulder 19. Theyieldable biasing force or the spring 21 is transmitted to the latchingdogs 9 which project and have radial slide movement within windows 22formed in the sleeve 20 of a size only slightly greater than the dogportions projected therethrough. The axial spacing between theseatingshoulder 16 and the windows 22 when the collar abuts the shoulder 19 isrelated to the axial spacing between the nipple landing seat 3 and thenipple keeper groove 4 so that in the landed position of the tool thelatch dogs 9 are aligned with the keeper groove 4.

Inwardly of the slide collar 20, each dog is extended upwardly anddownwardly, forming retaining ears '23 for co-operation with the insideface of the collar in limiting the range of outward dog projection. Thisinward portion of each dog 9 is located within and is of a verticaldimension of about half the length of an axially elongated slot 24extending through the wall of the housing part It} and is slidabletherein against elastic restraint of the coil spring 21. i

In their upper portions the tubular inner core 8 and the tubularhousing. part 10 have mating bearing surfaces of cylindricalconfiguration for a free sliding fit one on the other and below theslidably fitted surfaces, each cylindrical surface is stepped away fromthe ,other.* 'The reduction in diameter of the core 8 affords aperipherally relieved portion 25 for an axial distance corresponding atleast to the axial dimension ofthe inward face of the dog 9 and itsextensions '23. Immediately below the re; lieved portion 25, thediameter of the core 8 is enlarged to approximately the diameter of theenlarged internal diameter of the lower portion of the housing part 10so as to form an annular band enlargement or rib 26 which constitutes astop abutment against dog retraction when radially aligned with the dogs9. Below the band or 9' enlargement 26, the wall of the core8 is againof reduced external diameter, providing a peripherally relieved portion27. Separating the stepped internal diameters of the housing part 10 isa downwardly facing shoulder;,28 which provides a stop limitabutmentfontheupper shoulder 26' of the rib enlargement 26 upon relativeslide travel of the core and housing. When the housing and core are heldagainst relative slide travel, as seen in. Fig. l, the axial spacing ofthe shoulders 28- and 26' approximates. and should be at least as greatas the axial length. of the stop. abutment face of the rib enlargement26.

The upper end of the hollow core 8 has threaded on it a fishing neckadapter 29 which terminates in an enlarged head 30 over which can besnapped any of the conventional pulling tools, as indicated generally at31 inFig. 4. The bottom of the neck adapter 29 normally is seatedagainst the upper. edge of the upper housing element as a limit stop torelative core travel downwardly in .the housing. This is the initialposition of the partsas seen in Fig. l and is releasably maintained asby means of'a shear pin 32 extending through aligned openings formedpartly in each the core 8 and the housing element 10. A similar shearpin 33 is fitted to the upper end of the housing part 10 and to aconventional lowering tool 34 when the hanger is ready to be placed in awell.

In. use the hanger assembly secured to a running, or lowering tool 34.on the end of a wire line and with the core and housing releasablycoupled by the shear pin 32,v is lowered into the tubing string from thesurface and its lower end on reaching the landing nipple will enter thesame until the shoulder 16 contacts with the landing seat 3 and stopsfurther descent. In the final increment of downward hanger movement theoutwardly projected dogs 9 backed by the rib 26 will come into abutmentwith the landing seat 3 and temporarily will be held against furtherdescent as permitted by the housing slot 24 and the compressed length ofthe coil spring 21 while the housing slides in the sleeve or collar 20.Such relative movement carries the abutment rib 26 downwardly belowalignment with the stopped dogs 9 and as the rib moves from behind theinner faces of the dogs, the peripherally relieved core portion abovetherib comes into alignment with the dogs and receives the dogs fortheir radial retraction and inward slide travel out of bearing on thelanding seat 3. The inward relief or radial clearance is such that theouter tip portions of the retracted dogs can slide below the landingseat 3, as is indicated in Fig. 2, for accommodating continued descentof the tool assembly. At or just before the time the housing shoulder 16finally lands on the nipple seat 3, the inwardly retracted dogs willbecome aligned with the internal keeper groove 4 so that the dogs arefree to move outwardly into the groove and thenslide down in front ofthe enlarged rib 26 under the resilient force of the coil spring 21transmitted through the slide collar 20. With the dogs projected fromthe housing into the annular keeper groove and so maintained againstretraction by their inward abutment with the positioning rib 26, thelanded hanger will be securedly latched against accidental dislodgmentfrom the nipple, as shown in Fig. 3. As soon as the automatic latchingaction has been completed, an upward jar force on the running tool 34resisted by the latched-in housing will shear the pin 33 for removal ofthe wire line and running tool.

When retrievement of the hanger is desired at any later time, the usualwire line pulling tool 31 is lowered and snapped over the pickup head ofthe core 8, whereupon an upward jar transmitted through the wire linewill shear the pin 32 for releasing the connection between the core '8and the housing 10. Lift force will now raise the core relative to thelatched-in housing until the-upper shoulder 26' of the rib 26 comes intoabutn l'entl with the housing shoulder 28, at which time the rib 26-will also be out of radial alignment with the dogs 9- and the lowerrelieved portion 27 of' the core willprovide-clearancefor inwardretraction of the dogs out of the keeper notch 4 and for travel upwardlyas the assembly moves clear of the nipple. To assist inward and outwardcamming of the dogs in response to relative movement between the parts,the corners of the dogs are preferably beveled according to conventionalpractices as are their co-operating-camming surfaces on the rib 26 andthe nipple.

From the foregoing, it will be apparent that there has been provided animproved hanger which can be readily installed in a landing nipple witha self latching action for eliminating skilled manipulation asheretofore required for forcibly effecting an outward dog wedging aftera landing has been made and which latched-in assembly likewise canbeeasily removed when occasion arises. While only a single embodiment hasbeen de scribed, it is to be understood that modifications can be madesuch as come within the scope of the appended claims.

What is claimed is:

1. In a well tool, a tubular housing having a travel stop seat, a slidesleeve mounted on the housing for movement axially thereof, spring meansbearing downwardly on said sleeve and yieldably resisting upward slidetravel thereof, a fixed stop on the housing engageable by the sleeve atits lower limit of slide travel, a retractable-projectable dog radiallymovably mounted by the sleeve,vinterengageable surfaces on the dog andthe sleevedefining the outward limit of dog projection, said housinghaving an axially elongated slot slidably receiving the inner end ofsaid dog, a central core slidable within the housing, a releasableconnection between the housing and said core retaining the core againstrelative slide movement in the housing, a bearing abutment on said coreengageable with the inner end of the dog to maintain the same radiallyprojected from the sleeve when the latter is at its lower travel limit,a radially relieved portion on the core upwardly of said core abutmentand radially. aligned with the inner end of the dog when the latter iscarried upwardly with the sleeve, said relieved portion providingclearance for inward dog retraction and another relieved portion on thecore downwardly of said bearing abutment and movable with the core uponrelease of said connection and into radial alignment with the inner endof the dog and thereby providing clearance for inward dog retraction.

2. A well tool according to claim 1 in which said housing has a runningtool engageable head and said dog in its projected position during arunning-in operation being engageable with a landing nipple to stopdescent of said sleeve with the housing until said dog becomes radially,aligned with and retracts into said upper relieved portion of the coreand said core having a pulling tool engageable head through which upwardforce can be applied for releasing said connection and raising thedownward relieved portion of the core into radial alignment with thedog.

3. In a well tool, a hollow housing having a locating ,stop abutment andan upper bore portion of small diameter anda lower bore portion of largediameter, a downwardly facing shoulder separating said bore portions, 21core slidable in the housing and having axially spaced small and largediameter portions respectively received in said bore portions and havingan upwardly facing shoulder at the. junction of said portions of thecore for stop abutment with the housing shoulder, a releasableconnection joining the core and housing against relative slide travel ina position in which said shoulders are normally axially spaced apart, asleeve having a dog receiving window and being slidable on the housingbetween axially spaced apart positions in the lower of which said windowis radially aligned with the large diameter portion of said core and inthe upper of which positions said window is radially aligned with thesmall diameter portion of'the core above its shoulder, elastic meanspositioned on the housing in downwardly biasing -engagement on theslidable sleeve; said housinghaving an axially elongated window thereinaligned at all times with the window of the slidable sleeve, a radiallyrelieved portion on the core positioned below its large diameterportion, said large diameter portion being of an axial length less thanthe distance between the normally spaced apart shoulders and being outof alignment with said window in said sleeve when the sleeve is in itslower position in the elongated window ofsaid housing when the sleeveslides on the housing, said dog having a sleeve engageable stop abutmentagainst outwardly projected separation from the. sleeve and beinglaterally positionable by the sleeve in co-operation with said coreportions, said large diameter core portion, when aligned with the windowin said sleeve, abutting and maintaining the dog projected radiallyoutwardly of the housing and the other two core portions, when either isaligned with the window in said sleeve, afiording inward clearance forradial retraction of the dog.

4. In combination with a well tubing nipple having a tool landing seatand a keeper groove below the seat, a retrievable well tool hanger forremovable reception within said nipple, said hanger comprising a hollowhousing having an axially elongated slotin the side wall thereof andhaving a stepped diameter bore presenting a downward facing stopabutment above said slot, a core slidable in the housing between upperand lower limits, a releasable connection between the housing and coreholding the latter at its lower limit, a radial enlargement of the coreengageable with said abutment to establish the upper limit of core slidetravel when said connection is released, said enlargement being of anaxial length less than the length of said slot and being positioned inradial alignment with the lower part of the slot to provide clearanceinwardly of the upper part of the slot when said core is at its lowerlimit and being positioned in radial alignment with the upper part ofthe slot to provide clearance inwardly of the lower part of the slotwhen said core is at its upper limit, a lowering tool engageableformation on the housing for releasable suspension coupling with alowering tool, an external stop shoulder on the housing engageable withsaid landing seat when the slot is radially aligned with said keepergroove, a dog having a retaining portion thereon, dog retainer means onthe housing engageable with the dog and the retaining portion thereof tohold the dog against separation from the retainer means and slidablylocating the dog for axial travel within the slot between lower andupper positions, said dog in its lower position when the core is at itsupper limit being retractable from the keeper groove into the clearancebelow said enlargement and said dog when the core is at its lower limitbeing engageable with said enlargement to maintain the dog projected atits lower position and being out of engagement with said enlargement andradially aligned with the clearance thereabove for dog retraction at itsupper position, elastic force exerting means interposed between thehousing and the dog and active to bias said dog downwardly in its slotand a pulling tool engageable formation at the upper end of the corethrough which force can be transmitted first to release said connectionand then to lift the hanger from the nipple.

5. A well tool hanger for retrievable locked mounting in a tubing stringnipple and comprising a pulling tool engageable core having a dogprojectable abutment between the core and housing for holding'thesamewith said stop surfaces axially spaced apart a distance greater thanthe length of said abutment, said housing having an axially elongatedslot through the side thereof in radially overlapping relation with bothsaid abutment and the peripherally relieved portion thereabove when saidreleasable connection is effective and which slot is in radiallyoverlapping relation with the peripherally relieved portion below saidabutment when said stop surfaces are interengaged, a dog having aretaining portion thereon, dog retainer means carried by the housing andengageable by said dog and the retaining portion thereof and holding thedog in assembly relation with the housing, said dog being axiallyslidable in said elongated slot and radially shiftable therein foralignment with and inward retraction into said relieved portions and foralignment with and outward projection by said abutment and yieldablemeans on the housing having force transmitting relation with and biasingsaid dog downwardly in said elongated slot.

6. A well tool hanger for retrievable locked mounting in a tubing stringnipple and comprising a pulling tool engageable core having a peripheraldog projecting abutment and inwardly relieved dog receiving clearancesabove and below said abutment, a running tool engageable housingslidably enclosing said core and having an internal shoulder engageableby said abutment at the upper limit of slide travel ofthe core in thehousing, an external nipple seating surface on the housing, a releasableconnection joining the housing and the core and holding the same withsaid shoulder and abutment axially spaced apart, said housing having anannular peripheral groove whose top and bottom margins form lateralshoulders and having an axially elongated slot through the housing wallat'said groove and of a length to overlap at one end with the inwardclearance above said abutment when said clearance is efiective and tooverlap at the other end with the inward clearance below said abutmentwhen the latter is engaged with said internal shoulder, a slide collarfitted in said groove for travel to and from the bottom groove shoulder,a coil spring also fitted to said groove and bearing upwardly on the topgroove shoulder and bearing downwardly on said slide collar to yieldablybias the same downwardly, a nipple engageable dog held by said sleeveand radially projectable and retractable relative thereto and axiallyslidably fitted in said elongated slot for co-operation with saidabutment in the projection of the dog and with the inward clearance oneither side of said abutment in the retraction of said dog, andco-operating seating faces on the dog and said sleeve engageable withone another in holding the dog against separation from the sleeve.

7. In a well tool, a pulling tool engageable core having a dogprojecting abutment and inwardly relieved dog receiving clearances aboveand below said abutment, a running tool engageable housing slidablyenclosing said core and having an external stop surface thereon, areleasable connection joining the housing and core and holding the coreagainst upward slide travel in the housing co-operating shoulders on thecore and housing engageable as a limit stop to upward core slide travelrelative to the housing, a radially and axially shiftable dog and dogretaining and biasing means connecting the dog and housing againstseparation and acting on the dog to yieldably resist its axial movementupwardly relative to,

the housing from a position aligned with and projected radiallyoutwardly by said abutment, said dog upon relative axial movementbetween the dog and the housing when the latter is releasably connectedwith the core being shiftable out of alignment with the abutment andradially retractable into the dog receiving clearance above saidabutment and said core being slidable upwardly in the housing uponrelease of said connection to a position in which said abutment is outof alignment with the do;

for radial retraction of the dog into the clearance below said abutment;

8. In a retrievable well tool: to bepassed through a well: pipe, 8. pairoftubular membershaving'slidably sleeved interfitment, interengageablemeans on saidmernbets defining alimited range. of relative slide traveltherebetween, a releasable connection joining said members initially infixed position against relative slide travel, the wall surface of onemember'which faces the wall sur- -face of the other member havingaxially successive zones, -one of which is of relatively reduceddiameter and another of which is of relatively increased diameter, alaterally projectable latch dog, retaining means slidably holding saidlatch dog on the other member for movement relative thereto, bothaxially and laterally thereof, and for slide bearing engageament withsaid zones respectively during relative axial movement for control of.dog lateral movement and spring means carried by said other member inelastioforce, transmittingrelation to the dog and aetive while. saidvmembers are fixedly held by said releasable connection to bias the dogaxially to a normal position in lateral bearing engagement with: thezone of increased diameter and to yield for relative :axial dogtravelinto axial bearing engagement with; the other zone and active uponrelative slide travel of said members to one limit after release oftheir connection, to bias the dog; axially in position free of lateralbearing engagement with both zones.

References Cited in the file of this patent UNITED STATES PATENTS

